[Abstract Title]. - Society for Neuroscience

Topic: B.06.a. Docking and fusion
Support: NSF 0456578
Title: Identification of a new locus functioning in synaptic transmission through a screen for
genetic modifiers of the Drosophila calcium channel mutant, cac TS2
Authors: A. LUTAS, S. ACHARJEE, *F. KAWASAKI;
Biol & Ctr. Mol Cell Neurosci, Penn State Univ., University Park, PA
Abstract: Neurotransmitter release is triggered by calcium influx through presynaptic voltagegated
calcium channels. In Drosophila, the molecular basis of presynaptic calcium channel
function was defined through analysis of cac TS2 , a temperature-sensitive (TS) paralytic mutant of
the calcium channel α1 subunit gene, cacophony. The cac TS2 mutant has also served as a starting
point for further genetic analysis to broaden our understanding of the functions and interactions
of cac-encoded calcium channels. We have conducted a screen for second chromosome genetic
modifiers of cac TS2 and have begun to characterize a new mutation recovered as an enhancer.
Double mutants of cac TS2 and the new mutation, referred to as e(cac) 2902 , exhibited enhanced TS
paralysis relative to cac TS2 . Electrophysiological analysis revealed that e(cac) 2902 also enhanced
the TS synaptic phenotype of cac TS2 . Furthermore, the isolated e(cac) 2902 mutation in a cac +
genetic background produced a TS reduction in the EPSC amplitude, indicating that the
e(cac) 2902 gene product serves an important function in synaptic transmission. Meiotic mapping
placed the e(cac) 2902 mutation within cytological region 53A and 57F on the distal right arm of
the second chromosome and deficiency mapping further refined this position to a 9kb genomic
region. This region contains four genes which have not been implicated in synaptic transmission
and thus molecular and phenotypic characterization of e(cac) 2902 is expected to further define the
in vivo roles of specific gene products at native synapses.
Disclosures: A. Lutas, None; F. Kawasaki , None; S. Acharjee, None.
Poster
236. Neurotransmitter Release: Docking and Fusion
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 236.23/D23
Topic: B.06.a. Docking and fusion
Support: Grants-in-Aid for Scientific Research from Japan Society for the Promotion of Science
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